Persistent Discrepancies between Observed and Modeled Trends in the Tropical Pacific Ocean

Abstract The trends over recent decades in tropical Pacific sea surface and upper ocean temperature are examined observations-based products, an reanalysis the latest models from Coupled Model Intercomparison Project phase six Multimodel Large Ensembles Archive. Comparison is made using three metrics of (SST) trend—the east–west north–south SST gradients a pattern correlation for equatorial region—as well as change thermocline depth. It shown that generation persist not reproducing response to radiative forcing latter at far edge or beyond range modeled internal variability. observed combination shoaling lack warming cold tongue upwelling region similarly extreme limit behavior. persistence last century half trend toward enhanced gradient and, four five gridded datasets, gradient, also model concluded it extremely unlikely consistent with Instead, results support argument which key climate continue be unable simulate this aspect change.